The present invention relates to a fixed orthodontic wire retainer for maintaining the alignment of the teeth following orthodontic treatment. The appliance is used to form or adapt the wire to fit the teeth during the construction of the retainer.
Fixed orthodontic retainers have been used in orthodontics since the early part of the 20th century. To clarify the description of the invention certain dental terms should be understood. Upper and lower teeth are termed maxillary and mandibular teeth, respectively. Front teeth are anterior teeth and back teeth are posterior teeth. Anterior teeth are incisors and are named centrals, laterals, and cuspids in order from midline to posterior. Posterior teeth from anterior to posterior are first and second bicuspids and first, second, and third molars. Individual teeth are described according to their surfaces. The distal surface is towards the back of the mouth and the mesial surface is towards the front of the mouth. The lingual or palatal surface is on the tongue side of the teeth. The labial or buccal surface is on the cheek or lip side of the teeth The occlusal surface of a tooth is its chewing surface.
The orthodontic procedure for maintaining the teeth straight following orthodontic treatment involves a wire bonded to the inner surface of the front teeth, most commonly the lower anterior teeth. The general shape of the wire is that of an arch, but each mouth is different in size, shape, and form of the arch, requiring the preformed wire to be adapted to the lingual surfaces of the anterior teeth. The adaptation process intraorally is difficult; therefore, soft wires have been used which have made the adapting of the wire to the teeth easier, but the soft wire is easily deformed when worn by the patient. Another approach is to fit the wire to a mold of the patient""s teeth. The mold method is time consuming as it requires a mold made from an impression of the patient""s teeth, the wire fitted to the mold, and an additional visit for the patient to receive the lingual retainer. The fitting of the archwire in a patient""s mouth has been difficult because each time the archwire was placed in the mouth the plane of the archwire, in relation to the teeth, would be slightly different, which makes adapting wire to the lingual surfaces of the teeth slow and difficult. The fitting process required the archwire to be repeatedly placed in the s adjusted. The archwire could not be repeatedly placed in the same position in relation to the teeth, making the adapting bends difficult and slow. The premade lingual archwires have usually included orthodontic mesh pads for bonding to the lingual surfaces of the teeth, usually the cuspids. The mesh pads are integral with the archwire, requiring a variety of lengths of premade archwires. One variation of the mesh pads was a universal size where one of the mesh pads was adjustably positioned. The mesh pads increased the difficulty of fitting the archwire to the teeth because the pads must be fitted to the lingual surface the teeth in another dimension which was vertical to the horizontal plane of the arcuate archrire.
The present invention is directed to a retainer archwire forming apparatus for adapting an archwire to the inner surfaces of the teeth. The archwire, when bonded to the patient""s teeth, becomes a fixed lingual retainer which maintains teeth alignment following orthodontic treatment. The archwire forming apparatus consists of an arcuate archwire portion connected to a handle portion. The arcuate archwire portion is formed in the shape of an arch on a single plane, that plane being parallel to the occlusal plane of the teeth when the arcuate archwire is placed in the mouth during the fitting process. The handle portion is connected to the end of the arcuate archwire which corresponds with the left side of the mouth when the arcuate archwire is placed in the mouth. The axis of the handle is parallel to the plane of the arcuate archwire and extends away from the mouth at a 90 degree angle to the point of attachment to the arcuate archwire. The handle at its point of attachment to the arcuate archwire has a bayonet bend. The bayonet bend extends towards the occlusal plane of the teeth four to six millimeters, allowing the body of the handle to clear the teeth during the fitting process of the arcuate archwire portion.
The handle portion of the archwire forming apparatus must have sufficient length to be hand held. The outer portion, or left end, of the handle has a flat area to enhance the grip of the wire. The flat area is parallel to the plane of the arcuate archwire and is formed by placing two successive bends in the wire at the outer end of the handle away from the mouth. The bends are done at an 8 mm interval. The exact dimension or shape of the flat area is not critical, but the dimension must be large enough for the apparatus to the hand held in a stable manner during the fitting process. The flat area would also be useful if it were vertical to the horizontal plane of the arcuate archwire. The object of the invention is the ability to repeatedly place the arcuate archwire into the mouth in the same relative position to the patient""s anterior teeth.
The handle portion allows the lingual archwire appliance to be firmly held, allowing the arcuate archwire to be repeatedly positioned in the mouth in an identical manner. The ability to accurately reposition the arcuate archwire allows its adaptation to the teeth to be done easily with accuracy and efficiency.
In an alternative embodiment of the present invention the handle portion can also be comprised of different materials, such as polypropylene or plastics, attached to the arcuate archwire adhesively or mechanically.
In another embodiment of the present invention the handle can be attached to the arcuate archwire which includes orthodontic bonding pads for adhering the wire to the patient""s teeth.